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Health Concerns of Chronic Ingestion of Uranium in Drinking Water Chris Shuey, MPH Southwest Research and Information Center Albuquerque, NM [email protected] For Tó Łani Enterprises Puerco-LCR Water Quality Project July 24, 2015 Nahata Dziil Commission Governance
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2008 2009 2010 2011 2012 2013 2014 2015 2016
Ura
nium
in W
ater
, ug/
l
Uranium in Drinking Water (µg/l) Arizona Windsong Water Co., Sanders, AZ
Drinking water standard: 30 µg/l (USEPA, Navajo EPA)
Sources: ADEQ 2008-2015 (http://azsdwis.azdeq.gov/DWW_EXT/JSP/WaterSystemDetail.jsp?tinwsys_is_number=9&tinwsys_st_code=AZ); Tolani Lake Enterprises, 2015.
DiNEH water quality statistics compared with USEPA data
(Concentrations in mg/l; Radium and Gross Alpha in pCi/l ) DiNEH* (2003-2010)
MCL N Range Mean ± SE Med.
As 0.01 158 0-0.482 0.007±0.0399 0.00094
U 0.03 135 0-0.26 0.009±0.0286 0.00027
Se 0.05 157 0-1.0 0.014±0.082 0.0011
F 4.0 192 0-8.3 1.15±1.177 0.705
Ra 5.0 84 0-10.9 1.87±2.10 1.28
NO2 1.0 118 0-7.5 0.131±0.694 0
NO3 10.0 199 0-29.0 1.583±3.54 0.3
GA 15 26 0.3-21.7 5.15±5.012 3.99
Pb .015 154 0-0.021 .0012±0.0028 0
*All water sources in 20 chapters of Eastern Agency GA = Gross alpha radioactivity
USACE-USEPA* (1994-2000) MCL N Range Mean ± SE Med.
As 0.01 222 0-0.282 0.009±0.028 0.0028
U 0.03 222 0-0.286 0.0198±0.039 0.0076
Se 0.05 222 0-0.957 0.0094±0.07 0
Ra 5.0 222 0-8.2 0.56±1.7 0.6
GA 15.0 222 0-155 11.5±21.98 4.4
Pb 0.015 222 0.0.1 0.0029±0.012 0
Al** 0.05-2.0
222 0.61.9 0.84±4.8 0.08
*All water sources located in the western half of the Navajo Nation in Arizona and Utah **Aluminum has no MCL; the reference range given is the secondary drinking water standard GA = Gross alpha radioactivity
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The Basics of Uranium (Łeetso, or “yellow dirt”, may not be accurate)
Discovered in Russia in 1789
A heavy metal — the heaviest natural element (No. 92)
Abundance about 0.5-5 ppm (0.00005%-0.0005%) in the continental crust (1000x more abundant than gold) Carnotite, most common uranium mineral Yellow flecks or streaks in gray-black matrix
A mixture of three different weights of atoms, called isotopes:
U-238 (99.3%), U-235 (0.7%), U-234 (<0.05%)
U is radioactive (its atoms spontaneously decay, releasing energy as a new element is formed)
Primary uses:
1940s-1960s: fissile material for nuclear weapons 1960s – present: fuel for nuclear power 1980s – present: metal casings for field ordnance
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What are the elements that result from the decay of uranium, and what types of radiation do they emit?
Red circle indicates radionuclides often found in elevated levels in uranium
mine and mill wastes
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Radiation: Energy that
travels through space in the form of particles or waves
Non-ionizing radiation Light, heat, microwaves and
radio waves
Ionizing radiation (Greek symbol): energy sufficient to remove an electron from an atom or molecule alpha (α) particles beta (β) particles neutrons gamma (γ) rays (photons)
Father Sky-Mother Earth Interaction:
Types of Radiation
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How Does Uranium Get In You? Inhalation — breathing
uranium in air in mines and mills, hauling ore
(workers) living around mine waste dumps dust and erosion from rocks
Ingestion — eating and drinking substances that contain uranium drinking water: most important
pathway (about 80%) eating animals, plants
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Why is Uranium Harmful? Chemical toxicant: causes kidney
damage, disease (proximal tubules)
Radiotoxicity: causes lung and bone cancers from radioactive decay products
Dozens of scientific, medical studies over last 125 years
Studies of human populations exposed to low levels of uranium in drinking water
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Sites of Uranium Toxicity to the Kidney*: Proximal Tubules
AAP, RBP
Brush border Urinary space
Interstitium, blood side
Proximal & distal tubules Nephron
*Kidney toxicity based on animal, human studies of uranium ingestion through water; LOAEL = ~14.5 ug/l-water.
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Exposure continuum
Most of the environmental exposures we see in human uranium studies are in the chronic, low-dose region
Chronic ----------------------- Acute (long-term, over time) (immediate effects)
Generally, lower dose less risk However, Low concentration over longer exposure time higher cumulative dose, greater risk
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Community Exposures to Uranium About half of all Navajo Chapters have 1 or more uranium exposure sources
Map by T. Rock, DiNEH Project
No uranium exposures in Lupton area?
Puerco River Basin, New Mexico and Arizona. USGS WRI 94-4192, p. 4.
Waste water discharges from uranium mining and milling operations in Puerco River headwaters contributed to basin-wide contamination from 1960s into 1990s.
Puerco River Contaminant Source: Church Rock Uranium Mill Tailings Spill,* July 16, 1979
*Largest release of radioactive wastes, by volume, in US history
United Nuclear Corp. Uranium Mill Tailings Dam, July 16, 1979
Dam breach location, July 17, 1979
Livestock tracks in Puerco River downstream of spill, July 17, 1979
NMEID Sampling in Puerco R. after spill
Community leaders Larry J. King (L) and Robinson Kelly addressed long-term impacts of spill in 2009.
Photos courtesy of Southwest Research and Information Center, New Mexico Environmental Improvement Division, Albuquerque Journal.
Puerco River warning sign
1972
CRUMP radiation monitoring,
2002
1st removal action, 2007
2nd removal action, 2009
Northeast Church Rock Mine and Red Water Pond Road Community, 1972-2009
Mine water discharges to Pipeline Arroyo, 1969-1983: More radioactivity released to Puerco River system by mine
dewatering than 1979 tailings spill.
3rd removal action, 2012
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Father Sky-Mother Earth Interaction:
When removed from Nik’ashbááh, uranium is oxidized and moves rapidly in water
Does it dissolve slowly or quickly? Solubility
Where does it go? Transport:
U+4 ― in most undisturbed rocks and groundwater, insoluble
U+6 ― when brought to the surface and exposed to oxygen in the air, highly soluble
Modified from slide by J. deLemos, 2007
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20+ years of discharge of uranium mine water 450 gpm in 1963 to 5,200 gpm in 1982 Wirt (USGS, 1994): “effects of uranium mining can no
longer be identified in water and sediment samples from the Puerco or Little Colorado rivers”
1979 Church Rock Uranium Mill Tailings spill 94 million gallons; pH = 1.5; one-time “shock loading”
Gallup Wastewater Treatment Plant (1958-present) 6.1 million gallon release of raw sewage in 1988 2.4 million gallons treated effluent per day since 1989
Natural runoff Wirt: “high sediment concentrations cause streamflow to exceed
Federal standards for radioactive…and nonradioactive elements”
Historic Contaminant Discharges to Puerco River (from Shuey, 1992)
So where did the uranium go? Our results suggest that the low sediment uranium concentrations likely resulted from the dissolution and flushing of uranium during precipitation events. Surficial, weathered sediments are depleted of more soluble uranyl phases relative to deeper (>~20 cm) sediments. Source: J. DeLemos, et al. Rapid Dissolution of Soluble Uranyl Phases in Arid, Mine-Impacted Catchments near Church Rock, NM. EST, 2008. 19
1st Law of Thermodynamics, “Conservation of Energy,” suggests that uranium and other contaminants are concentrated somewhere in the Puerco-LCR system.